Solid-state light emitting diodes (LEDs) and hi-powered LEDs in particular, are becoming more and more common in both commercial and industrial applications due to characteristics such as good electrical efficiency, small size and weight, and rugged construction compared to other light sources such as incandescent bulbs. They are now frequently used in back-lighting units, street safety applications (including streetlights, traffic signals, traffic directors and arrows), automotive lighting applications (including emergency vehicle warning lights) and industrial applications in the form of warning lights and beacons, strobes, mini-bars, and the like.
As the LED market grows, companies that provide LED-based products are continually looking for ways of making their lighting systems more efficient and reliable, as well as making them more cost-effective for their consumers. A major consideration in the design of such systems is heat management as LEDs only convert about 30% of the electric energy they consume, into visible light. The remaining energy, about 70%, is converted into heat. If that heat energy is not conducted away from the LEDs it can have a detrimental effect on performance.
Many performance characteristics of LEDs are influenced by the operating temperature. For example, as the LED temperature increases excessively, the light output decreases, the color of the light emitted shifts and the forward voltage decreases. Most importantly, the reliability of the LED decreases with excessive temperature. As a result, a primary cause of LED failures is improper thermal management. Thermal management, therefore, is a primary design concern in LED systems.
There is a need for an improved LED array assembly which overcomes some of the difficulties inherent in the—prior art systems. In particular, it is desirable that an improved LED array assembly be compact, cost-effective and easily assembled, while still addressing the issue of thermal management in such systems.